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Automatic Network Failure Recovery is a new Bunny feature that was earlier impemented and vetted out in amqp gem. What it does is, when a network activity loop detects an issue, it will try to periodically recover [first TCP, then] AMQP 0.9.1 connection, reopen all channels, recover all exchanges, queues, bindings and consumers on those channels (to be clear: this only includes entities and consumers added via Bunny).
Publishers and consumers will continue operating shortly after the network connection recovers.
Learn more in the Error Handling and Recovery documentation guide.
Bunny now supports listeners (callbacks) on
ch.confirm_select do |delivery_tag, multiple, nack|
# handle confirms (e.g. perform retries) here
endContributed by Greg Brockman.
Publisher confirms implementation now uses non-strict equality (<=) for
cases when multiple messages are confirmed by RabbitMQ at once.
Bunny::Channel#unconfirmed_set is now part of the public API that lets
developers access unconfirmed delivery tags to perform retries and such.
Contributed by Greg Brockman.
Bunny::Channel#wait_for_confirms will now correctly block the calling
thread until all pending confirms are received.
Channel error information is now properly reset when a channel is (re)opened.
GH issue: #83.
the default value of Bunny::Consumer noack argument changed from false to true
for consistency.
Global prefetch is not implemented in RabbitMQ, so Bunny::Session#prefetch
is gone from the API.
Fixed a problem when a queue was not declared after being deleted and redeclared
GH issue: #80
Channel queue and exchange caches are now properly invalidated when queues and exchanges are deleted.
Heartbeats are now correctly sent at safe intervals (half of the configured
interval). In addition, setting :heartbeat => 0 (or nil) will disable
heartbeats, just like in Bunny 0.8 and amqp gem.
Default :heartbeat value is now 600 (seconds), the same as RabbitMQ 3.0
default.
Fixes a potential race condition between basic.consume-ok handler and
delivery handler when a consumer is registered for a queue that has
messages in it.
GH issue: #78.
Bunny now supports two authentication mechanisms and can be extended
to support more. The supported methods are "PLAIN" (username
and password) and "EXTERNAL" (typically uses TLS, UNIX sockets or
another mechanism that does not rely on username/challenge pairs).
To use the "EXTERNAL" method, pass :auth_mechanism => "EXTERNAL" to
Bunny.new:
# uses the EXTERNAL authentication mechanism
conn = Bunny.new(:auth_method => "EXTERNAL")
conn.startA new high-level API method: Bunny::Consumer#cancel, can be used to
cancel a consumer. Bunny::Queue#subscribe will now return consumer
instances when the :block option is passed in as false.
Bunny::Exchange#delete will no longer delete pre-declared exchanges
that cannot be declared by Bunny (amq.* and the default exchange).
Bunny::DeliveryInfo#redelivered? is a new method that is an alias
to Bunny::DeliveryInfo#redelivered but follows the Ruby community convention
about predicate method names.
Bunny::DeliveryInfo#delivery_tag had a typo which is now fixed.
Bunny now correctly lists RabbitMQ extensions it currently supports in client capabilities:
basic.nack- exchange-to-exchange bindings
- consumer cancellation notifications
- publisher confirms
Lightweight Publisher Confirms is a RabbitMQ feature that lets publishers keep track of message routing without adding noticeable throughput degradation as it is the case with AMQP 0.9.1 transactions.
Bunny 0.9.0.pre3 supports publisher confirms. Publisher confirms are enabled per channel,
using the Bunny::Channel#confirm_select method. Bunny::Channel#wait_for_confirms is a method
that blocks current thread until the client gets confirmations for all unconfirmed published
messages:
ch = connection.create_channel
ch.confirm_select
ch.using_publisher_confirmations? # => true
q = ch.queue("", :exclusive => true)
x = ch.default_exchange
5000.times do
x.publish("xyzzy", :routing_key => q.name)
end
ch.next_publish_seq_no.should == 5001
ch.wait_for_confirms # waits until all 5000 published messages are acknowledged by RabbitMQIt is now possible to register a consumer as an object instead of a block. Consumers that are class instances support cancellation notifications (e.g. when a queue they're registered with is deleted).
To support this, Bunny introduces two new methods: Bunny::Channel#basic_consume_with
and Bunny::Queue#subscribe_with, that operate on consumer objects. Objects are
supposed to respond to three selectors:
:handle_deliverywith 3 arguments:handle_cancellationwith 1 argument:consumer_tag=with 1 argument
An example:
class ExampleConsumer < Bunny::Consumer
def cancelled?
@cancelled
end
def handle_cancellation(_)
@cancelled = true
end
end
# "high-level" API
ch1 = connection.create_channel
q1 = ch1.queue("", :auto_delete => true)
consumer = ExampleConsumer.new(ch1, q)
q1.subscribe_with(consumer)
# "low-level" API
ch2 = connection.create_channel
q1 = ch2.queue("", :auto_delete => true)
consumer = ExampleConsumer.new(ch2, q)
ch2.basic_consume_with.(consumer)If RABBITMQ_URL environment variable is set, Bunny will assume
it contains a valid amqp URI string and will use it. This is convenient
with some PaaS technologies such as Heroku.
It makes more sense for beginners that way.
Bunny::Queue#subscribe support the new :block option
(a boolean).
It controls whether the current thread will be blocked
by Bunny::Queue#subscribe.
Bunny::Exchange#publish now supports :key as an alias for
:routing_key.
Bunny::Session#queue, Bunny::Session#direct, Bunny::Session#fanout, Bunny::Session#topic,
and Bunny::Session#headers were added to simplify migration. They all delegate to their respective
Bunny::Channel methods on the default channel every connection has.
Bunny::Channel#exchange and Bunny::Session#exchange were added to simplify
migration:
b = Bunny.new
b.start
# uses default connection channel
x = b.exchange("logs.events", :topic)q.subscribe(:exclusive => false, :ack => false) do |delivery_info, properties, payload|
# ...
endBunny::Channel#fanout, Bunny::Channel#topic, Bunny::Channel#direct, Bunny::Channel#headers,
andBunny::Channel#default_exchange are new convenience methods to instantiate exchanges:
conn = Bunny.new
conn.start
ch = conn.create_channel
x = ch.fanout("logging.events", :durable => true)Bunny < 0.9.x example:
h = queue.pop
puts h[:delivery_info], h[:header], h[:payload]Bunny >= 0.9.x example:
delivery_info, properties, payload = queue.popThe improve is both in that Ruby has positional destructuring, e.g.
delivery_info, _, content = q.popbut not hash destructuring, like, say, Clojure does.
In addition we return nil for content when it should be nil (basic.get-empty) and unify these arguments betwee
-
Bunny::Queue#pop
-
Consumer (Bunny::Queue#subscribe, etc) handlers
-
Returned message handlers
The unification moment was the driving factor.
Bunny::Client#write now raises Bunny::ConnectionError instead of Bunny::ServerDownError when network
I/O operations fail.
Instead of reusing channel instances, Bunny::Client.create_channel now opens new channels and
uses bitset-based allocator to keep track of used channel ids. This avoids situations when
channels are reused or shared without developer's explicit intent but also work well for
long running applications that aggressively open and release channels.
This is also how amqp gem and RabbitMQ Java client manage channel ids.
Bunny::ServerDownError is now an alias for Bunny::TCPConnectionFailed